Universal typewriter ribbon spool

ABSTRACT

Internal and external hubs are provided with a ribbon retaining flange fixed to each to form respective first and second spool halves with the hubs fitting together in a telescoping manner and with first and second drive engaging means on opposite sides of the spool to properly engage at least two types of typewriters. Both drive engaging means are preferably formed on the first spool half that includes the internal hub. A third drive engaging means or spline is formed on the second half having the external hub and is exposed when the spool is separated. The internal hub has a central bore to fit one mounting spindle and removable sleeve to reduce the bore to fit a smaller spindle. The internal hub presents axially extending radial arms frictionally engaging the inside of the external hub; opposed axially extending tabs on two arms receiving the spline on the external hub to rotatably fix the spool halves together. The first spool half is molded plastic and the second spool half is metal for improving the frictional holding interface and for reinforcement.

United States Patent [1 1 Landgrai [4 1 Sept. 3, 1974 UNIVERSAL TYPEWRITER RIBBON SPOOL [76] Inventor: Walter David Landgraf, 9228 S.

Kildare Ave., Oak Lawn, 111. 60453 [22] Filed: Mar. 17, 1971 [21] Appl. No.: 125,179

Primary ExaminerJohn W. Huckert Assistant Examinerlohn M. Jillions Attorney, Agent, or Firm-Hyman l-lurvitz [57] ABSTRACT Internal and external hubs are provided with a ribbon retaining flange fixed to each to form respective first and second spool halves with the hubs fitting together in a telescoping manner and with first and second drive engaging means on opposite sides of the spool to properly engage at least two types of typewriters. Both drive engaging means are preferably formed on the first spool half that includes the internal hub. A third drive engaging means or spline is formed on the second half having the external hub and is exposed when the spool is separated. The internal hub has a central bore to fit one mounting spindle and removable sleeve to reduce the bore to fit a smaller spindle. The internal hub presents axially extending radial arms frictionally engaging the inside of the external hub; opposed axially extending tabs on two arms receiving the spline on the external hub to rotatably fix the spool halves together. The first spool half is molded plastic and the second spool half is metal for improving the frictional holding interface and for reinforcement.

4 Claims, 7 Drawing Figures UNIVERSAL TYPEWRITER RIBBON SPOOL The present invention relates to the improved construction of a spool for typewriter ribbon, and more particularly, to a spool for universal use.

BACKGROUND OF THE INVENTION Heretofore it has been proposed to provide means for adaptinga typewriter spool to fit more than one typewriter. These efforts have usually consisted of providing an adaptor hub to fit on the inside of the enlarged hub of an integrally formed spool. One such spool and adaptor combination is shown in the US. Pat. No. 2,873,839 issued to J. W. H. Bishop on Feb. 17, 1959. The adaptor is in effect a loose part in these prior combinations and thus apt to 'be lost or inadvertently disposed of by the customer as being an unnecessary part. Further, the prior art adaptors since they are an extra piece add substantially to the cost of a completed universal ribbon spool, and yet do not in any significant way add to the strength of the spool.

OBJECTIVES OF THE INVENTION Accordingly, it is one object of the present invention to provide a universal typewriter ribbon spool that overcomes the above objections and shortcomings.

It is another and more specific object to provide a universal typewriter ribbon spool divided into first and second spool halves with at least first and second drive engaging means on opposite sides of the spool so that loose part adaptors are not required.

It is another object of the present invention to provide a spool formed of mating halves wherein a third adaptation is provided by utilizing one half alone, and it is a further and related object to provide still another adaptation by simply using a removable sleeve.

It is still another object of the present invention to provide a two-part typewriter ribbon spool that fits together through telescoping hubs with an improved frictional holding interface, and improved strength characteristics.

BRIEF DESCRIPTION OF THE DISCLOSURE Briefly describing the invention, a ribbon spool comprises an internal and external hub each with a ribbon retaining flange to form respective first and second spool halves. First and second drive engaging means are provided on opposite sides when the halves are mated together to form a complete spool so that more than one typewriter may be properly engaged by merely turning the spool over. The internal hub has radial arms that are exposed adjacent the flange of the second half to drive the spool on one machine, and the second driving means is formed on the flange of the first half to engage another type of driving mechanism on a typewriter. Both primary drive engaging means are thus formed on one half, but still another or third drive engaging means is exposed on the second half when the halves are separated; this being in the form of an inwardly directed spline. Further adaptation is provided by a removable sleeve snugly fitting inside the central bore of the complete spool.

The internal hub is formed as a spider member with the radially extending arms, the axially extending edges of which frictionally engage the inner face of the exterior hub; the peripherally spaced axial lines of engagement sewing to attain increased frictional holding capacity. Preferably, the first spool half is integrally molded plastic that not only allows the two drive engaging means to be efficiently formed, but also permits improved frictional holding against the second spool half that is fabricated of substantially rigid sheet metal. The arms of the internal hub grip the metal more efficiently since they are capable of being impressed into the face of the external hub thereby increasing the static friction coefficient and thus the holding force. Once the static holding force is overcome, the sliding frictional coefficient is substantially reduced so that the halves may be easily separated. Opposed axially extending tabs on two of the internal hub arms serve to receive the inwardly directed driving spline on the external hub to rotatably position and fix the spool halves together.

Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by me of carrying out my invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a complete spool constructed in accordance with the teachings of the present invention with a portion of one flange and ribbon cut away for clarity;

FIG. 2 is an exploded view showing the parts of the two spool halves;

FIG. 3 is an enlarged top view of the spool of FIGS. 1 and 2;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a view of the spool on the side opposite that shown in FIG. 3; FIG. 6 is a cross-sectional view taken along line of FIG. 2; and

FIG. 7 is the external hub unrolled prior to fabrication.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to FIGS. 1 and 2 of the drawings, a more detailed look at the preferred embodiment of the present invention may be taken. In these Figures is shown a typewriter ribbon spool 10 having a typical ribbon R wound thereon in a conventional fashion. The spool 10 comprises a first spool half, generally designated by the reference numeral 11, and a mating second spool half 12. As best shown in FIG. 2, the second spool half 12 includes a rolled tubular hub 13 to which is attached a ribbon retaining flange 14 by conventional connector tabs 15. The hub 13 and the flange 14 are preferably fabricated of metal to afford strength and rigidity to the combination spool 10. The features of the hub 13 may be suitably formed by punched out porimpaling prongs 18 are provided by cutouts 19 to attach the end of the ribbon R. Tab-like side extensions on opposite ends of the unrolled hub are struck up during fabrication to form an axially extending spline within the external hub, for a purpose as will be seen presently.

The first spool half 1 l is integrally molded plastic and includes a spider-like hub 25 and a ribbon retaining flange 26. The hub 25 has a central bore 27 that is adapted to fit the upwardly extending spindle of one or more types of typewriters. Extending outwardly on the hub are radial arms comprising enlarged base portions 28 and reduced extensions 29. The axially extending peripheral edges 30 of the extensions 29 (see FIG. 2) thus provide narrow line faces that engage the inner face of the hub 13 to lock the two spool halves l1, 12 together. It is important that these edges are narrow or reduced, since the two hubs 25, 13 can be assured of a snug fit when the parts are mated. This is so since the entire peripheral engaging force is concentrated at only a few points around the hub or, put it another way, along a few lines extending axially along the hubs. This increased force causes the extensions 29 to grip the mating face of the hub 13 with substantially increased static frictional holding capability.

Molding the first spool half 11 of plastic also has advantages of greater strength and reduced cost of fabrication. The hub 13. and the flange 14 of the second spool half 12 are also interconnected for greater strength and are fabricated of relatively stiff sheet metal. Since the edges 30 of the arms of the hub 25 are plastic and thus relatively soft, they are impressed into the minute irregularities of the metal face of the hub 13 and thereby further improve the static frictional holding force between the spool halves. The frictional interface thus formed between the spool halves resists initial disengagement when the spool halves are attempted to be separated. This makes for a more desirable spool since there are no loose parts to come apart during handling or use. Once the static friction is overcome, the sliding friction of the plastic over the metal is not great so that the further separation of the parts can take place with ease.

One of the main objectives of the present invention is to provide a spool combination that is capable of properly engaging substantially all types of typewriters. However, since the spool driving mechanisms are well known, it is deemed not necessary to illustrate and describe the same herein. If a more detailed description of the mechanisms than given below is desired, reference may be made to any one of a number of US. patents in this field, including the above-named Bishop patent.

A first adaptation of the spool is the case wherein the spool is positioned in the typewriter as in FIG. 1 with the first spool half 11 on the bottom. As thus properly engaged with a first type of typewriter, such as a Royal standard or Haida standard or portable typewriter, downwardly extending drive lugs 35 engage the driving mechanism (not shown), and the upstanding spindle of the mechanism (alsonot shown) extends with a slip fit into the central bore 27 to allow for spool rotation. A ribbon reverse lever 36 is held in a slot in the flange 26, and is positioned in the full line position of FIG. 4 when ribbon is wound on the spool and pivots to the dotted line position when the ribbon reverse mechanism is to be activated. The lever 36 has a pair of bent ears 37 on opposite sides of the lower leg thereof (see FIG. 5) that engage raised knobs 38 when in the reversing position to maintain the lever captive within the slot.

Another use of the spool on another type of typewriter is possible when said spool 10 is turned over for insertionon the driving mechanism. In the second mode, the central bore 27 again serves as a support for thespool and spaces 40 between the arms 28, 29 serve to capture the orbiting drive pin of the driving mechanism. Among the mechanism useable when the spool 10 is so positioned include certain models of the Underwood standard and portable, Royal portable, Teletype, Hermes standard and portable and various other machines. It will be noted that the space 40 can receive drive pins positioned at various radii from the spindle since it matters not whether the base 28 or the extension 29 is engaged to turn the spool.

On a selected adjacent two arms of the hub 25 are provided axially extending peripheral tabs 41 (see FIG. 3) that terminate in free edges that serve to receive the spline 20 therebetween. The spool halves 11, 12 are thus angularly positioned and rotatably fixed with respect to each other. At this angular position on the internal hub 25, spline 20, mentioned above, forms a portion of radial space 42, which particular space is normally selected by the customer to receive the drive pin of the mechanism, since the hub is substantially reinforced by the presence of the spline 20 and thereby provides a preferred driving engagement.

A third adaptation of the spool 10 takes place when the spool half 11 is removed from the spool half 12 to expose the spline 20. It would be noted in this regard that the ribbon remains on the second spool half 12. With the flange 14 in the down position, the hub 13 may be placed over the drive mechanism of certain noiseless core type machines of the Remington and Underwood manufacture. In this mode of operation, the spool is operating without an upper ribbon retaining flange; however, this has proven to not present any difficulty of control of the ribbon. The spline 20 engages the mating core of the driving mechanism.

Still another possibility of adaptation of the spool 10 of the present invention is provided by a removable sleeve 45 that is receivable in the inner or central bore of the internal hub 25. The sleeve 45 is dimensioned so as to snugly fit in the bore. It is preferably made of a split metal bushing to provide increased static frictional holding capability, thus preventing the same from falling out during handling of the spool. The removal of the sleeve from the inner bore leaves the same dimensioned to provide the necessary operative slip fit on a spindle of still another type of typewriter, including the Adler and Norm typewriters. For economy, the sleeve 45 may be a piece of split metal with the desired internal and external dimensions and cut to the necessary length.

From the above description, it will be clear that several advantageous improvement features have been incorporated in the universal spool 10. The spool is made for maximum strength in two spool halves with telescopically engaging internal and external hubs integrally attached to respective ribbon retaining flanges and without the separate adaptor of the prior art. First and second drive engaging means are provided on opposite sides of the composite spool; one drive engaging means being at the end face of the internal hub of the first spool adjacent the flange on the second half, and another drive engaging means formed on the opposite flange of the same first spool half. An internal spline is exposed when the second spool half is disengaged from the first, said second half thus being useable by itself on still another type of typewriter. Still other typewriters are adapted by removing a reducing sleeve fitted within the inner bore of hub 25. The hubs matedly engage in a novel fashion in order to maintain a tight fit and thus absolute integrity of the composite spool during handling and use.

In this disclosure, there is shown and described only the preferred embodiment of the invention, but, as aforementioned, it is to be understood that the invention is capable of use in various other combinations and environment and is capable of changes or modifications within the scope of the inventive concept as expressed herein.

I claim:

I. A cylindrical typewriter ribbon spool having an axis, comprising internal and external hubs having equal lengths parallel to said axis, a ribbon-retaining flange fixed to each of said hubs to form respective first and second spool halves, said hubs having a snug frictional fit over their entire lengths to form a complete spool, and first and second drive-engaging means of respectively diverse types and located on and integral with one of said spool halves, one of said driveengaging means located externally of said flanges, wherein said internal hub is formed as a spider member having radially extending arms, and wherein slots are formed between the radially inward base portions of said arms, said slots extending entirely through said spool parallel to said axis to define said second type of drive engaging means, said arms including circumferentially smaller, axially extending edges which frictionally engage the internal face of said exterior hub, whereby spaced axial lines of engagement between said hubs exist to provide static frictional holding capability.

2. A cylindrical typewriter ribbon spool having an axis, comprising internal and external hubs having equal lengths parallel to said axis, a ribbon-retaining flange fixed to each of said hubs to form respective first and second spool halves, said hubs having a snug frictional fit over said entire lengths to form a complete spool, and first and second drive-engaging means of respectively diverse types and located on and integral with one of said spool halves, one of said driveengaging means located externally of said flanges and the other being a slot extending entirely through said spool parallel to said axis, wherein said internal hub is formed as a spider member having radially extending arms, the outer axially extending edges of said arms frictionally engaging the internal face of said exterior hub, whereby spaced axial lines of engagement between said hubs exist to provide static frictional holding capability, wherein said external hub includes an inwardly directed spline forming a third drive-engaging means when said first spool half is removed, two peripherally directed axially extending tabs opposing each other on the edges of two of said radially extending arms, said tabs serving to receive said spline therebetween to rotatably position and fix said spool halves together.

3. A cylindrical typewriter ribbon spool having an axis, comprising internal and external hubs having equal lengths, taken parallel to said axis, a ribbonretaining flange fixed to each of said hubs to form respective first and second spool halves, said hubs having a snug frictional fit over said entire lengths to form a complete spool, and first and second drive-engaging means of respectively diverse types and located on and integral with one of said spool halves, one of said driveengaging means located externally of said flanges and the other being a slot extending entirely through said spool parallel to said axis, wherein said internal hub is formed asa spider member having radially extending arms, the outer axially extending edges of said arms frictionally engaging the internal face of said exterior hub, whereby spaced axial lines of engagement between said hubs exist to provide static frictional holding capability, wherein said external hub includes an inwardly directed spline forming a third drive-engaging means when said first spool half is removed, two peripherally directed axially extending tabs opposing each other on the edges of two of said radially extending arms, said tabs serving to receive said-spline therebetween to rotatably position and fix said spool halves together, wherein said first spool half is integrally molded plastic and said second spool half is fabricated of sheet metal, whereby the edges of the plastic arms of the internal hub form a frictional holding interface with the inner face of the metal exterior hub.

4. A typewriter spool having an axis, including an external hub, said hub being a thin metallic annulus, a metallic flange extending axially from one edge of said hub, an internal hub fabricated of plastic, a plastic flange integral with said internal hub, first projections extending from said plastic flange, said internal hub having plural radially extending arms fabricated of said plastic and an axial aperture extending entirely through said internal hub, said radial arms having thin line ends bearing directly against the inner wall of said metallic hub, said plastic hub including radial slots extending parallel to the axis of said hub and constituting drive engaging means, two of said radially extending arms including circumferentially extending second projections which project towards each other with a predetermined circumferential spacing, said metallic hub including circumferentially located radially inwardly projecting arms having said predetermined circumferential spacing, whereby said second projections and said projecting arms interlock when said hubs are assembled, said hubs being separable to provide a single flange spool, wherein said first projections provide driven elements, said metallic flange having an aperture to expose said plastic hub. 

1. A cylindrical typewriter ribbon spool having an axis, comprising internal and external hubs having equal lengths parallel to said axis, a ribbon-retaining flange fixed to each of said hubs to form respective first and second spool halves, said hubs having a snug frictional fit over their entire lengths to form a complete spool, and first and second drive-engaging means of respectively diverse types and located on and integral with one of said spool halves, one of said drive-engaging means located externally of said flanges, wherein said internal hub is formed as a spider member having radially extending arms, and wherein slots are formed between the radially inward base portions of said arms, said slots extending entirely through said spool parallel to said axis to define said second type of drive engaging means, said arms including circumferentially smaller, axially extending edges which frictionally engage the internal face of said exterior hub, whereby spaced axial lines of engagement between said hubs exist to provide static frictional holding capability.
 2. A cylindrical typewriter ribbon spool having an axis, comprising internal and external hubs having equal lengths parallel to said axis, a ribbon-retaining flange fixed to each of said hubs to form respective first and second spool halves, said hubs having a snug frictional fit over said entire lengths to form a complete spool, and first and second drive-engaging means of respectively diverse types and located on and integral with one of said spool halves, one of said drive-engaging means located externally of said flanges and the other being a slot extending entirely through said spool parallel to said axis, wherein said internal hub is formed as a spider member having radially extending arms, the outer axially extending edges of said arms frictionally engaging the internal face of said exterior hub, whereby spaced axial lines of engagement between said hubs exist to provide static frictional holding capability, wherein said external hub includes an inwardly directed spline forming a third drive-engaging means when said first spool half is removed, two peripherally directed axially extending tabs opposing each other on the edges of two of said radially extending arms, said tabs serving to receive said spline therebetween to rotatably position and fix said spool halves together.
 3. A cylindrical typewriter ribbon spool having an axis, comprising internal and external hubs having equal lengths, taken parallel to said axis, a ribbon-retaining flange fixed to each of said hubs to form respective first and second spool halves, said hubs having a snug frictional fit over said entire lengths to form a complete spool, and first and second drive-engaging means of respectively diverse types and located on and integral with one of said spool halves, one of said drive-engaging means located externally of said flanges and the other being a slot extending entirely through said spool parallel to said axis, wherein said internal hub is formed as a spider member having radially extending arms, the outer axially extending edges of said arms frictionally engaging the internal face of said exterior hub, whereby spaced axial lines of engagement between said hubs exist to provide static frictional holding capability, wherein said external hub includes an inwardly directed spline forming a third drive-engaging means when said first spool half is removed, two peripherally directed axially extending tabs opposing each other on the edges of two of said radially extending arms, said tabs serving to receive said spline therebetween to rotatably position and fix said spool halves together, wherein said first spool half is integrally molded plastic and said second spool half is fabricated of sheet metal, whereby the edges of the plastic arms of the internal hub form a frictional holding interface with the inner face of the metal exterior hub.
 4. A typewriter spool having an axis, includIng an external hub, said hub being a thin metallic annulus, a metallic flange extending axially from one edge of said hub, an internal hub fabricated of plastic, a plastic flange integral with said internal hub, first projections extending from said plastic flange, said internal hub having plural radially extending arms fabricated of said plastic and an axial aperture extending entirely through said internal hub, said radial arms having thin line ends bearing directly against the inner wall of said metallic hub, said plastic hub including radial slots extending parallel to the axis of said hub and constituting drive engaging means, two of said radially extending arms including circumferentially extending second projections which project towards each other with a predetermined circumferential spacing, said metallic hub including circumferentially located radially inwardly projecting arms having said predetermined circumferential spacing, whereby said second projections and said projecting arms interlock when said hubs are assembled, said hubs being separable to provide a single flange spool, wherein said first projections provide driven elements, said metallic flange having an aperture to expose said plastic hub. 